Lesson 4: Using Identities to Solve Equations

 

Focus

 

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A mechanic is planning to fix a car. She has taken down a set of imperial wrenches, but finds all the bolts on the car are metric and her wrenches don’t fit properly. What should she do? Clearly, she should switch the imperial wrenches for a metric set so they are useable.

The halves of an identity can be thought of as the two wrench sets; each part is useful at different times. To use an identity, you can switch one half of the identity for the other to make an expression easier to work with.

 

Lesson Outcomes

 

At the end of this lesson you will be able to

• simplify expressions using trigonometric identities
• solve equations using trigonometric identities

Lesson Question

 

You will investigate the following question:

• How can trigonometric identities be used to solve problems?

Assessment

 

Your assessment may be based on a combination of the following tasks:

• completion of the Lesson 4 Assignment (Download the Lesson 4 Assignment and save it in your course folder now.)
• course folder submissions from Try This and Share activities
• additions to Glossary Terms and Formula Sheet
• work under Project Connection